Australian 50 cents 1966 -- fake or genuine?

Dear Community,

Is this Australian 50-cent 1966 piece a copy or original?

Its weight is 12.85 g, diameter – 31.5 mm, thickness – 2 mm.

Actual photos are attached.

Why would somebody go in the trouble of faking such coin?

Yes, generally I also think so, but the facts are stubborn things, as they say: the thickness is only 2 mm (against 2.5 g of normal coin) and the  weight is only 12.85 g (against 13.28 g normative weight). How can it be, given it is a silver (i.e. precious metal) coin? Is this within these coins' remedium?

Here is a link to the coin in the catalogue for ease of reference.

Now, have you tried to weigh another one that you believe is authentic? And if so, what is the result?

I'm asking because it could be that the scale is off. In addition, while the diameter is accurate, it seems to me it's not always easy to measure the thickness of a coin accurately. As a matter of fact, on a few occasions I have seen that the thickness in the catalogue is wrong. This may be because this info is not provided in the SCWC catalogues and was measured somewhat carelessly (e.g. with a ruler instead of a caliper) by whoever filled that line on the coin page.

I'm not saying this is what happened; just that it is a possibility. Your coin certainly doesn't look fake.

Dear Camerinvs,

Thank you for your attention to my topic.

1. "... have you tried to weigh another one... it could be that the scale is off".

Unfortunately, I don't have any other sample of this coin at hand, but anyway my scale can have +/-0,05 g error, but not >0.4 g... :) I've checked that with reference weights.

2. "...(with a ruler instead of a caliper) by whoever filled that line..."

In general -- yes, this may be the case in some occasions. In my specific instance I measured both the diameter and the thickness with a precise metal caliper.

3. "Here is a link to the coin in the catalogue for ease of reference."

Thank you. And here are links to this coin in two other resources:

https://www.ramint.gov.au/collect/national-coin-collection/circulating-coins/fifty-cents

https://www.coinsandaustralia.com/coins-articles-australia.php?article=decimal-1966-half-dollar-the-silver-50-cents-coin&id=5

As can be seen from them, The Royal Australian Mint doesn't give its thickness, but states that the diameter is 31.65 mm., while some private Coinsandaustralia site states that its diameter is 31.5 mm and thickness is 2 mm, in line with the mine. Be that as it may, the both are unanimous on the weight, which is greater than the weight of my piece...

4. "Your coin certainly doesn't look fake."

Yes, I also think so, and that's why the fact of its more than 3% underweight seems especially perplexing. Was such a discrepancy normal at the mint for the 800 Silver?

I have one and it's about 12.37+ g. Mine is in a coin holder and I am too lazy to remove and place it on the scale. Mine is in an excellent condition, like almost in BU condition. I bought this from a local dealer many years ago. No reason to believe this is a fake.

ahkai

I have one and it's about 12.37+ g. Mine is in a coin holder and I am too lazy to remove and place it on the scale. Mine is in an excellent condition, like almost in BU condition. I bought this from a local dealer many years ago. No reason to believe this is a fake.

Dear ahkai,

Thank you for the information.

However, how do you know its exact weight if you say you are reluctant to properly weigh it?

Alex5555

Yes, generally I also think so, but the facts are stubborn things, as they say: the thickness is only 2 mm (against 2.5 g of normal coin) and the  weight is only 12.85 g (against 13.28 g normative weight). How can it be, given it is a silver (i.e. precious metal) coin? Is this within these coins' remedium?

Mine is 2.08 mm thick. It's not a normal coin, so you cannot compare measurements.

Sjoelund

 

Mine is 2.08 mm thick. It's not a normal coin, so you cannot compare measurements.

Dear Sjoelund,

Thank you for your response, but could you please specify what exactly you mean by 'It's not a normal coin, so you cannot compare measurements.' in the context of current discussion?

It is the only coin with the km#67, so there are no “normal” other coins to compare it with. From 1967 the coins got the km#68, and they have a thickness of  2.35 to 2.58mm in my collection!

I hope that's clear?

yvon

Why would somebody go in the trouble of faking such coin?

Because it’s silver ?? This coin looks genuine to me without seeing it in hand 

Typical Mint tolerance on weight in the US at the time was +/- 4%. 13.28 g is the target weight, +/- 4% is 12.75 g to 13.81 g.  At the time a silver coin was a normal composition so there would be no need to hold to a tighter tolerance on the coin for all 36 million of them.  Ignore the thickness in Numista. It is a user input and subject to differences in measurement techniques.  Prove to yourself the coin is silver (XRF, density, ice cube…) and you're done.  Nobody is going to counterfeit this coin in silver.

Alex5555

ahkai

I have one and it's about 12.37+ g. Mine is in a coin holder and I am too lazy to remove and place it on the scale. Mine is in an excellent condition, like almost in BU condition. I bought this from a local dealer many years ago. No reason to believe this is a fake.

Dear ahkai,

 

Thank you for the information.

 

However, how do you know its exact weight if you say you are reluctant to properly weigh it?

 

 

I weighted the coin together with the coin holder and then weight an empty holder. My weight is just an estimate.

This should help…..

The Thickness on the Numista page is incorrect.

N#6761

 I have fixed it. It was entered a long time before I became referee for Australia. 

I have never bothered to do a check on it. But now I have.

Your coin is genuine.

Regards Mike

Hi Mike,

you never thought about changing your caliper to a metal one with 0.00 precision. Those plastic ones are not extremely reliable in their results, I had one for ONE year and found out that I had up to plus/ minus 0.1 difference with a metal caliper, which my wife gave me for XMas!

brismike

This should help…..

 

 

 

Is that 2.0 also the thickness of the rim?  Looks like you're measuring on the field. 

Dear colleagues,

Thank you all for your input. (And sorry for the delay in response...)

1.

rsirian1

Typical Mint tolerance on weight in the US at the time was +/- 4%. 

Dear rsirian1,

This piece of information is really interesting, both with respect to our specific case and in broader sense. Could you please give any reference to the source of such information? It would be useful to have it at hand, should the necessity arise…

brismike

 

Your coin is genuine.

 

Regards Mike

Dear Mike,

Thank you. Yes, in general I also tend to think so, judging solely by its visual appearance. But then how can the fact of is underweight be explained? Is it really an allowed remedium for Australian silver coins of this type, by analogy with the fact for American coins, cited by rsirian1? Or is it anything else?

3.

As for the thickness measurement of my specimen: my metal caliper shows 2 mm sharp when measured along the coin's rim. The way of measurement shown on the last photo (i.e. along the coin's devices, not touching the rim) gave me 1.9 mm, which seems to be fully consistent with the 'protective' nature of a rim on a coin.

Alex5555

Dear colleagues,

 

Thank you all for your input. (And sorry for the delay in response...)

 

1.

rsirian1

Typical Mint tolerance on weight in the US at the time was +/- 4%. 

Dear rsirian1,

 

This piece of information is really interesting, both with respect to our specific case and in broader sense. Could you please give any reference to the source of such information? It would be useful to have it at hand, should the necessity arise…

 

I made a study of all the Euro coins in my collection some time ago and this is the result for the weights!

1 cent

2 cents

5 cents

10 cents

20 cents

50 cents

1 euro

2 euro

If you send me your email address, I can send the raw data from my collection from then.

Sjoelund

 

I made a study of all the Euro coins in my collection some time ago…

Dear Sjoelund,

Thank you, your research result is generally interesting. 

That's a pity it can't be fully used to explain the current specific case due to the disparate nature of the object of your study and the coin in question. :)

In my data I have the weights, the diameter and the thicknesses, which help you to understand deviations from “standard” and that's what the discussion was about?

Sjoelund

In my data I have the weights, the diameter and the thicknesses, which help you to understand deviations from “standard” and that's what the discussion was about?

Dear Sjoelund,

Thank you for your readiness to generously share the results of your research. 

However, I believe that directly extrapolating your otherwise undoubtedly interesting data on the modern Euro coins to  the 800 Silver Australian 50 cent 1966 coins won't be quite correct thing to do, will it? In my humble opinion, it will be too broad an analogy to rely upon, in this specific case…

I think that any reliable known information on the remedium, i.e. the maximum officially permissible deviation in a coin's weight and purity, for the Australian 50 cent 1966 will be much more effective to solve the question, rather than making a guess based upon actual statistical data on coins from completely different time, region, denominations, alloys etc…

Alex5555

… any reliable known information on the remedium…

For example, rsirian1 in his post provided very useful information on the American coins of that time, so it would be really interesting to know the source of it, for possible future use and references in discussions on American coins of that period; and may be Mike (brismike), being the referee to Australian coins on this site, will be able to share some similar info for the Australian silver coins of this type, if ther is any…

Here's a good article on US coin tolerances.  https://www.thesprucecrafts.com/how-much-do-coins-weigh-4171330

In practice, like all well controlled high volume production processes, the actual variation of most is smaller than the limits (~ +/- 2%).  Similar to what Ole showed, here's a plot of US quarter weights:

And for US pennies:

To show Ole's data above in a similar graph I used his data to to make these:

rsirian1

Here's a good article on US coin tolerances.  https://www.thesprucecrafts.com/how-much-do-coins-weigh-4171330

Dear rsirian1,

Thank you very much, the article is really serviceable for possible reference discussing American coins.

As for me, I get the pith of it, for this topic's specific case, as the following:

“The composition of United States coinage is determined by laws passed by the US Congress and approved by the President. The Coinage Act of April 2, 1792, established the denominations and specifications that the Treasury Department could direct the US Mint to manufacture.”

and

“Kennedy half-dollars minted from 1965 through 1970 have a composition of 40 percent silver and 60 percent copper and weigh 11.5 grams with a tolerance of ± 0.4 grams.”

Now what is left is to find any similar information on the Australian 50 cents 1966 coin – I hope that Mike (brismike) would assist us with that.

Note that even the Kennedy 40% silver coins have a weight tolerance of +/- 3.5%.

rsirian1

Note that even the Kennedy 40% silver coins have a weight tolerance of +/- 3.5%.

Yes, certainly. 

Now what's interesting is the tolerance for its Australian counterpart, with its twice as much silver content…

I wouldn't necessarily expect a much tighter tolerance. A coin's weight is determined by the weight of the blank which is determined by the thickness of the sheet and the diameter of the punch.  When 36 million are made it doesn't make sense to hold the weight too tight. The cost of scrapping overweight blanks is more that the cost (at the time) of the little extra silver.  Obviously, just conjecture on my part.